hw/loongarch: Add LoongArch load elf function.

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220606124333.2060567-40-yangxiaojuan@loongson.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

hw/loongarch/loongson3.c

@@ -19,6 +19,8 @@
 #include "exec/address-spaces.h"
 #include "hw/irq.h"
 #include "net/net.h"
+#include "hw/loader.h"
+#include "elf.h"
 #include "hw/intc/loongarch_ipi.h"
 #include "hw/intc/loongarch_extioi.h"
 #include "hw/intc/loongarch_pch_pic.h"
@@ -29,6 +31,36 @@
 
 #include "target/loongarch/cpu.h"
 
+static struct _loaderparams {
+    uint64_t ram_size;
+    const char *kernel_filename;
+} loaderparams;
+
+static uint64_t cpu_loongarch_virt_to_phys(void *opaque, uint64_t addr)
+{
+    return addr & 0x1fffffffll;
+}
+
+static int64_t load_kernel_info(void)
+{
+    uint64_t kernel_entry, kernel_low, kernel_high;
+    ssize_t kernel_size;
+
+    kernel_size = load_elf(loaderparams.kernel_filename, NULL,
+                           cpu_loongarch_virt_to_phys, NULL,
+                           &kernel_entry, &kernel_low,
+                           &kernel_high, NULL, 0,
+                           EM_LOONGARCH, 1, 0);
+
+    if (kernel_size < 0) {
+        error_report("could not load kernel '%s': %s",
+                     loaderparams.kernel_filename,
+                     load_elf_strerror(kernel_size));
+        exit(1);
+    }
+    return kernel_entry;
+}
+
 static void loongarch_devices_init(DeviceState *pch_pic)
 {
     DeviceState *gpex_dev;
@@ -200,15 +232,29 @@ static void loongarch_irq_init(LoongArchMachineState *lams)
     loongarch_devices_init(pch_pic);
 }
 
+static void reset_load_elf(void *opaque)
+{
+    LoongArchCPU *cpu = opaque;
+    CPULoongArchState *env = &cpu->env;
+
+    cpu_reset(CPU(cpu));
+    if (env->load_elf) {
+        cpu_set_pc(CPU(cpu), env->elf_address);
+    }
+}
+
 static void loongarch_init(MachineState *machine)
 {
     const char *cpu_model = machine->cpu_type;
+    const char *kernel_filename = machine->kernel_filename;
     ram_addr_t offset = 0;
     ram_addr_t ram_size = machine->ram_size;
     uint64_t highram_size = 0;
     MemoryRegion *address_space_mem = get_system_memory();
     LoongArchMachineState *lams = LOONGARCH_MACHINE(machine);
+    LoongArchCPU *lacpu;
     int i;
+    int64_t kernel_addr = 0;
 
     if (!cpu_model) {
         cpu_model = LOONGARCH_CPU_TYPE_NAME("la464");
@@ -234,17 +280,28 @@ static void loongarch_init(MachineState *machine)
                              machine->ram, 0, 256 * MiB);
     memory_region_add_subregion(address_space_mem, offset, &lams->lowmem);
     offset += 256 * MiB;
-
     highram_size = ram_size - 256 * MiB;
     memory_region_init_alias(&lams->highmem, NULL, "loongarch.highmem",
                              machine->ram, offset, highram_size);
     memory_region_add_subregion(address_space_mem, 0x90000000, &lams->highmem);
-
     /* Add isa io region */
     memory_region_init_alias(&lams->isa_io, NULL, "isa-io",
                              get_system_io(), 0, LOONGARCH_ISA_IO_SIZE);
     memory_region_add_subregion(address_space_mem, LOONGARCH_ISA_IO_BASE,
                                 &lams->isa_io);
+    if (kernel_filename) {
+        loaderparams.ram_size = ram_size;
+        loaderparams.kernel_filename = kernel_filename;
+        kernel_addr = load_kernel_info();
+        if (!machine->firmware) {
+            for (i = 0; i < machine->smp.cpus; i++) {
+                lacpu = LOONGARCH_CPU(qemu_get_cpu(i));
+                lacpu->env.load_elf = true;
+                lacpu->env.elf_address = kernel_addr;
+                qemu_register_reset(reset_load_elf, lacpu);
+            }
+        }
+    }
     /* Initialize the IO interrupt subsystem */
     loongarch_irq_init(lams);
 }

target/loongarch/cpu.h

@@ -308,6 +308,8 @@ typedef struct CPUArchState {
     AddressSpace address_space_iocsr;
     MemoryRegion system_iocsr;
     MemoryRegion iocsr_mem;
+    bool load_elf;
+    uint64_t elf_address;
 } CPULoongArchState;
 
 /**